MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a magnetic recording medium having an excellent preservable property by incorporating at least nitrogen atoms and oxygen atoms into a thin ferromagnetic film and increasing the atomic number ratio of the oxygen incorporated in the thin ferromagnetic film with respect to iron gradually from near the surface of the thin film toward a substrate. CONSTITUTION:The thin ferromagnetic metallic film which is formed on the nonmagnetic substrate and consists essentially of iron is provided as the magnetic layer. At least the nitrogen atoms and oxygen atoms are incorporated into the thin metallic film and the atomic number ratio of the oxygen incorporated in the thin ferromagnetic film is increased gradually from near the surface of the thin film toward the substrate. For example, an ion gun 6 is operated to form an iron oxynitride film at the time of fixing the nonmagnetic substrate 2, melting and evaporating the iron material 4 and depositing the film thereof on said substrate. Rust resistance is thereby improved and the adhesiveness between the substrate and the thin magnetic film after the long term preservation is simultaneously improved. The preservable property is markedly improved.